Categories of special nuclear material

 

The NRC groups special nuclear materials and the facilities that possess them into three categories based upon the materials’ potential for use in nuclear weapons or their “strategic significance”:

• Category I: High strategic significance
• Category II: Moderate strategic significance
• Category III: Low strategic significance

The NRC’s physical security and safeguards requirements differ by category, with Category I facilities subject to more stringent requirements because they pose greater security and safeguards risks.